This invention relates to the field of remanufacturing toner cartridges for use in electrophotographic devices such as printers, copiers, and facsimile machines. These toner cartridges typically contain a number of components in addition to toner. Remanufacturers of toner cartridges take used toner cartridges, clean them, replace any worn out components, and add new toner. The resulting remanufactured or recycled toner cartridge is then sold, generally at a discount compared to a new cartridge.
Remanufacturers have used a variety of different methods to remanufacture toner cartridges. U.S. Pat. No. 5,223,068 to Raymond Baley discloses one such method of remanufacturing a toner cartridge.
The method of remanufacturing a toner cartridge is dependent upon the original design of the toner cartridge. Some remanufacturers contend that changes in the design of toner cartridges by the original equipment manufacturer (OEM) are done, at least in part, to defeat remanufacturing. Whether this reason for OEM design changes is true or not, it is true that changes in the design of a cartridge by the OEM create new difficulties for remanufacturers. Most of these difficulties center on disassembling the cartridge in a way that allows for fast and economical cleaning, replacing of worn components, and adding new toner.
A recent design change by the OEM in a cartridge called the HP 9000 has a dramatically different design from previous toner cartridges. The HP 9000 is substantially larger, holding much more toner than previous toner cartridge designs. The HP 9000 has end caps that are welded onto the full width of the toner cartridge. The end caps apparently give the cartridge greater strength, and help hold the toner hopper/developer roller housing/waste bin sub assembly. Before the introduction of the HP 9000 most toner cartridges had a toner hopper attached to a developer roller housing, and flexible film seal heat-sealed to the sealing surface of the toner hopper. The toner hopper/seal/developer roller housing assembly in turn was mechanically connected to the waste bin. The mechanical connection to the waste bin was accomplished with the use of one or more pins. The toner hopper was attached to the developer roller housing by ultrasonic welds at the seam between them. These welds were readily accessible from the exterior and could be sawed apart or wedged apart. Once remanufacturers separated the developer roller from the toner hopper, the remanufacturer could easily access the components in the toner hopper and developer roller housing and could easily reseal the toner hopper.
The HP 9000 has a unique construction. It is anticipated that other OEMs will make toner cartridges of similar construction in the future. The toner hopper and developer roller housing are not welded directly together. Instead they are each separately heat sealed to a specialized seal assembly. This seal assembly has an accordion connector that is heat sealed to an intermediate plate. The intermediate plate is ultrasonically welded to the toner hopper, and the opposite end of the accordion seal is heat sealed to the developer roller housing. The accordion pleats are heat sealed together. The toner hopper and the developer roller housing are thus indirectly connected together. The waste bin section of the HP 9000 attaches in the usual manner to this toner hopper/developer roller housing by use of a pin, and a spring connection. The toner hopper and waste bin are then held in a fixed relationship to one another by two rigid end caps that run the entire width of the cartridge and that are welded onto the toner hopper and the waste bin. The developer roller housing floats relative to the waste bin ensuring that the developer roller and OPC drum maintain a proper relationship. Embedded in one of the end caps near the location of the welds are a variety of electrical contacts that provide the necessary voltages to the different components of the toner cartridge.
The use of the end caps coupled with the electrical connection between one of the end caps, and the sub assembly behind them create unique problems for the remanufacturer. First, end caps must be separated in such a way as to not sever the electrical connections hidden inside them. Secondly, the end caps must be removed in such a way as to allow for reattachment of these end caps.
The seal used in the HP 9000 also presents issues of complexity. Rather than simply heat sealing a seal to a toner hopper, the OEM in the HP 9000 heat seals a metallized film to the toner hopper sealing surface. This metallized film in turn has a tail that is attached to the one end of the seal and extends back over the seal to the other side of the cartridge. The end of the tail is threaded onto a spool. That spool is contained within a housing attached to the toner hopper and concealed within one of the end caps. The toner hopper has electrical contacts on the surface of the toner hopper. These toner hopper contacts are designed to be in electrical contact with a pair of conductive traces on the surface of the OEM seal. When the end-user places the cartridge into the printer, the printer senses whether the seal is in place by sensing whether the electrical connection between the contacts are in place. If there is an electrical connection between both sets of contacts, then the printer will cause the spool to wind, removing the seal from over the toner hopper discharge opening and breaking the electrical connection of the first contact, but not the second contact. If the printer does not sense at least the second contact, then it will not print at all. Therefore, any replacement seal must emulate the electrical characteristics of the OEM seal.
Finally, this new construction causes problems in the way the toner hopper and developer roller housing are to be reattached after this assembly. As mentioned above, the OEM heat seals each of these members to an intermediate plate, or an accordion seal. The intermediate plate and accordion seal are destroyed in the process of any separation of the toner hopper from the developer roller housing. In remanufacturing the toner cartridge, it is difficult to maintain the right stack height between the developer roller housing and the toner hopper as well as to firmly adhere the two together.
The present method of remanufacturing as described below solves these and other problems associated with remanufacturing cartridges with construction similar to the HP 9000. This method further facilitates rapid and repeatable remanufacturing of these cartridges.
The method of remanufacturing toner cartridges with two end caps that run the full width of the toner cartridge is as follows:
First, the end caps of the toner cartridge must be separated from the toner hopper/developer roller housing/waste bin sub assembly. The end caps have been welded onto the sub assembly. The preferred method is to cut the end cap welds deeply enough to separate the end caps, but not so deeply as to damage the end cap electrical contacts. Two templates are used to control location of cutting on these end caps. Cuts are made through the template openings through the welds between the end caps and the toner hopper/developer roller housing/waste bin sub assembly. In the preferred embodiment the first template and second template are clamped together across the toner cartridge and then placed in a frame which allows the cartridge to be rotated during cutting. The first and second templates may be made of plastic, but in the preferred embodiment are made of aluminum. There is a first axle connected to the first template and a second axle connected to the second template. The first and second axle rest on a first and second upright respectively. The first and second uprights together make the frame. In the preferred embodiment, the first and second upright are tall enough to allow the toner cartridge to be completely rotated facilitating cutting of the weld through the template opening. In a preferred embodiment a base connects the first and second upright providing additional stability to the toner cartridge splitter.
The first template has first template openings. The second template has second template openings. These openings correspond to the welded sections of the end caps. In the preferred embodiment, a router, or other rotary cutting tool, is used to cut the end cap welds. The cut locations are controlled by the location of first and second template openings. The depth of cut is controlled by a retractable bit enclosure that exposes the desired amount of cutting but the retractable bit on closure is pressed against the templates at the template openings. The desired depth of cut is necessary to cut the weld on the end caps without damaging the end cap electrical contacts.
After the end cap welds are cut on the toner cartridge splitter, the toner cartridge is removed from the toner cartridge splitter and the end caps are pulled from the toner hopper/developer roller housing/waste bin sub assembly. Some minor cutting or wedging may need to be done to facilitate this removal. If so, a box cutter or pocketknife can be used. The waste bin is separated from the developer roller housing by removing the toner cartridge pin and disassembling the spring. The waste bin may then be cleaned, and any worn components in it may be replaced.
The remaining section of the toner cartridge consists of the toner hopper and developer roller housing together with the seal. These may be separated by sawing them in half, by wedging apart the welds between them or by cutting the accordion seal with a knife. In so separating the toner hopper from the developer roller housing, the seal intermediate plate is loosened, and should be discarded. The old seal itself should be removed and discarded. The seal spool cover should be removed. The spool cover is generally heat tacked or glue tacked on the toner hopper. It may be separated by use of a screwdriver, knife, or other wedging tool. The old seal is removed from the spool, and any traces of the old seal should be cleaned from the toner hopper sealing surface.
Now the new seal may be attached to the toner hopper sealing surface. The tail of the removable seal should be threaded through the spool. The spool cover should be replaced and tacked down. In the preferred embodiment glue is used to reattach the spool cover. It is not important that this attachment result in a tight seal around the spool cover.
The preferred embodiment of the new seal has the following construction which aids in the reconstruction of the toner cartridge. The preferred embodiment of the replacement seal has a first gasket layer with a first side and a second side and the gasket opening. A removable seal layer is attached to the second side of the gasket. The removable seal layer has a first side, a second side, and a first end and a second end with a tail attached to the second end. An electrically conductive trace is attached to the second side of the removable seal layer at the first end. A second gasket layer is attached to the second side of the removable seal layer. The removable seal layer preferably has a two-part construction. A metallized film is attached to the first gasket and a polypropylene ribbon material is attached to the metallized film. The metallized film provides strength to the removable seal while the polypropylene ribbon material can be oriented so that the removable seal preferentially tears in the desired direction. In the preferred embodiment the first side of the first gasket layer has a pressure sensitive adhesive layer attached to it. In use this layer of pressure sensitive adhesive attaches the seal assembly to the toner hopper. The removable seal layer which is attached to the second side of the first gasket layer completely covers the gasket opening. The combination of these two elements seal the toner in the toner hopper. The removable seal layer has a tail at its second end. The tail of the removable seal layer is folded back over the length of the seal toward the first end. This first end of the removable seal layer is placed closest to the seal spool. This end of the tail of the removable seal is threaded onto the spool. On top of the removable seal layer and attached to both the removable seal layer and the first gasket layer is a second gasket layer. The second gasket layer is attached to the removable seal layer, or to the removable seal layer and first gasket layer below. This is on the first side of the second gasket layer. In the preferred embodiment, the second side of the gasket layer is attached to a layer of pressure sensitive adhesive. In use, this pressure sensitive adhesive layer attaches the seal assembly to the developer roller housing. By use of this construction, the seal itself creates the connection between the toner hopper and the developer roller housing.
After replacing the worn components, and replacement of the seal over the toner hopper, the remanufacturer may now add new toner through the toner fill hole by removing the old plug, adding toner and replacing the plug. If necessary, a new plug may be placed in the toner fill hole. After new toner is added, the toner hopper and developer roller housing are reattached. In the preferred embodiment, the reattachment is through use of the seal discussed above. The developer roller housing is attached to adhesive on the second side of the second gasket. Added support for this connection will come through use of the end caps. After the toner hopper and developer roller housing are connected, the waste bin section is reconnected to the developer roller housing by use of a toner cartridge pin and spring. The end caps are now ready to be reattached.
Although the end caps may be glued or welded back into place, in the preferred embodiment, the end caps are replaced in a manner that facilitates easy removal for a second remanufacturing. In the preferred embodiment a series of clips are screwed into the end caps at set locations. These screw clips can then be clamped to the body of the toner hopper/developer roller housing/waste bin sub assembly. Clips without screws may be used, however, screws make for a tighter connection. The screws are also easily removable and reusable. In an alternate embodiment, clips that clip onto discrete locations of the end cap and to the body of the toner hopper/developer roller housing/waste bin sub assembly are used.